We stayed at the JW Marriott for 2 nights in mid-March. The service was impeccable and our rooms were extremely comfortable. The rooms were a nice size and pleasantly decorated. This hotel has connecting room so is good for families that need more than one room. We have absolutely no complaints at all. The Brickell Village is an up and coming neighborhood just a couple of blocks away with a great Italian restaurant and a French Bistro.
The fitness room was well appointed and the pool with it's stainless steel sides and bottom was just terrific. We stayed on the 7th floor which opened to the pool and had outside space. We had lunch by the pool and room service breakfast one morning and all was on par with what you would expect from hotel room service.
There were complimentary bottles of water at turndown and also in the fitness room. It seems that they thought of everything to keep their guests comfortable.